Does anyone have an idea what could cause the loud metalic noise in my rebuilt 727. The noise sounds like the teeth on the flexplate hitting the thin inspection cover. However, that's not the problem....it just sounds like that. I attempted to start the rebuilt 383 and when it initially started I heard the noise and shut it off. It was quite loud. I took the inspection cover off and everything looks great. It makes the noise in both neutral and park. I double checked the linkage adjustments and tried starting it again and again the noise persisted. I thought about disconnecting the converter from the flexplate/engine and trying to start the new engine again but I suspect it's not like a Chevy and this cannot be done.

one thing to look for is the small dust sheild that goes between starter n trans. it might be bent. another is the bolts on the pulley on the dampener. if too long they may hit the timeing cover. I have done this before changing a four pulley over to a single and not adding washers or changing bolts. good luck n let us know what you find.

I checked the bolts on the balancer and they are not making contact with the cover. I used the original bolts. Also, the inspection shield looks perfect....no signs of impact or contact.

has the engine and trans been apart?

was the tc fully engauged to the pump lugs?

if not it could have busted the front pump...

did you have to pull the tc up to the flex plate?

if not it was not fully engauged...

are the tc bolt tight?

i have had them back out and hit the block as it was turning..sound like a rod knock at first...

flex plate could be cracked...

has the oil pan been off?

could be something hitting the pick up tube...

Yes both the engine and trans have been apart to rebuild both. I thought the TC was fully engaged but could be wrong. If the front pump was destroyed would the loud noise continue to be present when attempting to start the engine again?
Can the TC be unbolted from the flex plate now and then attempted to re-engage it, or does the entire trans have to be pulled?

Check the starter itself.

I had a problem that sound alot like what you have going on.

The start would engage but the plastic part that retracts the gear was broken and it was gringding agaisnt the teeth on the torque convertor.

Sounded alot like the torque convertor bolts grinding on the dust cover.

is the converter full? could the noise be the torque converter rattling around until it gets pumped full of fluid?

I was working on a 59 T-bird that hadn't been started in several years. first time I started it up, it made a horrible sound, I [Edited by Moparts - Keep it clean] it off and checked converter bolts...they were loose. so I tightened them, started it back up, made another noise, and I started searching, looking, listening, but before I could find it, it went away.

best I could figure was that the converter drained back all the fluid and was rattling around until it filled up again.

The converter bolts have thin heads. If you replace them with standard bolts or use washers then they will likely hit. Other likely possibilities have already been mentioned above.

The 727 will make that noise if you shift into park with the wheels turning. Maybe the park mechanism is installed incorrectly?